


Brotherly Love

by overdose



Category: Ao no Exorcist | Blue Exorcist
Genre: Alternate Universe - Modern Setting, First Time, Half-Sibling Incest, Hand Jobs, M/M, Masturbation, Public Blow Jobs, lots of sin
Language: English
Status: Completed
Published: 2018-04-24
Updated: 2018-04-24
Packaged: 2019-04-07 10:02:25
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 2,980
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/14078448
Author URL: https://archiveofourown.org/users/overdose/pseuds/overdose
Summary: Living in a full house makes it difficult for Mephisto to love his half-brother, Rin. That doesn't stop him from going at it.





	Brotherly Love

A house full of four teenage boys involves several things. They can be loud, filthy, fight with each other, or they can all hate each other and shut themselves in like losers.

For the twins Rin and Yukio, they got introduced to their half-brothers months ago. Mephisto and Amaimon decided to crash at their place. Shiro, their adoptive father, had no quarrels about this. "The more the merrier!" he said.

The four brothers socialized like any siblings would. Rin and Amaimon would argue all the time. Yukio would scold and bicker with Amaimon for being lazy and disrespectful. Mephisto, the older of the bunch, didn't care and observed their affairs from afar. They also had their close moments, like now.

Whoever lost this fighting game would have to go by pizza out their own money. Shiro was out helping out in church, and he told the boys to go buy food with their money. Rin is sitting on his bed next to Mephisto, playing against Yukio who sat in a chair. Amaimon stuffed his face with candy on the floor, about to fall asleep.

Mephisto sneakily snaked his arms around Rin. The younger boy shivers at the touch, trying to stay focused. The loud noises blaring from the TV muffles their conversation. "Do your best~" Mephisto grins, hands moving down to the boy's lap.

"What are you doing?!" Rin asks in a harsh whisper, turning his head. The distraction causes Rin to lose a health bar. "Hey!" he shouts, a response to both his lost and Mephisto's hand that squeezed his flaccid cock.

"Try harder, Rin." Yukio states without looking back, starting the next round. "Loser buys pizza, remember?" he shouts.

"Yeah. O-Okay." The shaky words escape Rin as he pulls a blanket over himself. It doesn't stop Mephisto from sliding his hand in Rin's shorts. "What the fuck, Mephisto?" he mutters again.

"Hm?" Mephisto responds, tilting his head. "Focus on the game, Rin." His hand begins stroking Rin's cock beneath the cover. Rin growls. To the other boys in front of them, the noise is related to the game. Mephisto feels the boy's cock harden, and he chuckles.

"Please..." Rin quietly whines, his grip on the controller tightens.

Mephisto pauses the stroking. "I'll stop if you want."

Rin bites his lip. "No!" he shouts, realizing Yukio is kicking his ass in the game. It's also a response to Mephisto, who continues jerking Rin off. "No, no, no!" The boy mashes the buttons, trying to get this over with. This hasn't happened before. Rin savors it. Despite Mephisto being his brother, he silently urges him to continue. Soon, with a restrained groan, Rin spills all over his underwear and Mephisto's hand.

"You lost!" Yukio stands up proudly, setting his controller down. Before he turns to face Rin, Mephisto licks his sticky hand and gets up from the bed. "Oh, Mephisto, can you drive Rin?"

"Of course~" Mephisto grins. "Come on," he says to Rin. "And wake up." he kicks Amaimon's sleeping body. Amaimon groans and rises.

With a gulp, Rin nods. "I-I'm coming," he was about to stand up until he realized his shorts were stained. "Uh, I gotta change. Everyone leave."

His twin nods and exits the room. Amaimon soon follows, dragging his body. Before Mephisto disappears, he winks at Rin, shutting the door. Rin collapses on his bed. He processes what happened. For some odd, sick reason, he didn't mind what Mephisto did. He wanted more.

The car ride to the pizza place wasn't calm at all. The moment their car left the driveway, Rin sighed. "Want to explain what you did?" he asks, turning the radio down. "I'm not mad. Or disgusted..." a blush rises to his cheeks. "I want to know why."

Mephisto chuckles, lifting a hand so he can brush Rin's cheek. "What is there to say?" he asks, slow to his own doings. "We're brothers." the car stops at a red light. "...that won't stop me from loving you, of course. You're very irresistible, Rin~"

It's a compliment that turns Rin's face redder than before. "It's wrong," he blurts out. "It's - It's weird! We're brothers..." Rin bites his lip. They only share the same father, not mother...

"Well, alright," Mephisto replies as he parks their car in the pizza place, turning to Rin. He unbuckled his seatbelt, ready to leave. "I understand - Ah," his response is interrupted by Rin's tender lips.

They kiss deeply in the parking lot. Anyone could see them, and anyone could judge. They kept going until they couldn't breathe. A satisfied moan leaves Mephisto when they separate. Rin pants, but that doesn't make him quit. His tongue is deep into Mephisto's mouth. "Oh, fuck," Rin curses, clouded by lewd thoughts. His dick begins to pulse in his pants. "Mephisto..."

"I know~" Mephisto grins. He opens the car door, wiping his mouth. "We'll continue later. Let's order the food. Wouldn't want the others to starve..."

Rin glares. Mephisto wants the boy to suffer. They enter the pizza place to order their food. As usual, it takes 30 minutes. After Rin pays, Mephisto nudges him and eyes the bathroom with a smirk.

He's crazy, Rin thinks. But it's a late night on a weekend and the store is empty... He follows Mephisto into the restroom. When they realize it's vacant, they're making out in a locked stall against the door.

"Hard again, Rin~?" Mephisto quietly asks, nibbling Rin's ear. "You can't be too greedy... What if I want something, too~?"

Rin grabs Mephisto's crotch. "O-Okay!" he's shy, dropping to his knees as he pulls down the elder's pants. Mephisto is taller, so Rin has to kneel to face Mephisto's hardened member. He takes the length in carefully, trying to make it wet as possible.

Is this his first time sucking someone off? Mephisto can't tell. Rin is too good at this, thrusting his head down Mephisto's cock, his mouth watering as his tongue licks the slit. "What a good boy~" Mephisto runs his hand through Rin's dark hair. He groans, feeling his cock drip into the boy's mouth. "Keep going, little brother~"

"Mmmf," Rin mumbles, nearly gagging as his face meets Mephisto's crotch. He intends to drag this out. Slowly, he moves in and out of Mephisto, training his mouth to capture all his cock. His eyes begin to tear up. Loud sucking noises and groans fill the quiet restroom.

Mephisto bites his lower lip watching Rin go at it. He could come right then and there watching the boy blush and cry while sucking him off. He's dreamed of this for so long and it's finally happening. "I'm close, Rin," Mephisto gasps as he cups his brother's cheek.

Rin brings in a deep breath as he removes his lips from the throbbing cock in front of him. "Aaah," he opens his mouth, face red.

"Already such a whore~?" Mephisto smirks, positioning his wet cock in Rin's vulnerable mouth. With a few strokes, he groans and releases in Rin's mouth. His sticky seed drips from the boy's lips. "Rin..." he blushes and lifts his brother's chin up, wiping the mess he made.

"Ah..." Rin stands up. The enclosed space caused his body to tense up. When Mephisto nudges and kisses him against the stall, he immediately melts. "L-Let's go-" he whispers. "Before someone enters..."

Mephisto kept a still face and nodded. He wanted to fuck Rin in the sink right there, but he held himself back. They fix each other's clothes and washed before exiting. It was a miracle no one entered. With a suspicious eye, the cashier hands over the food to the pair.

"What the hell took you guys so long?!" Amaimon shouts when Mephisto and Rin enter their home. He snatches the pizza from Rin and begins digging in. Yukio follows behind him, eating as well. "You suck, Rin!"

"What was that?!" Rin glares at Amaimon, raising his fist. The two brothers were forehead to forehead, yelling at each other. Mephisto quietly chuckles.

"Will you guys stop?" Yukio sighs, pushing up his glasses. "And don't talk with your mouth full, Amaimon."

They grumble and separate before returning to their food. After what happened, Rin isn't even sure if he's hungry. He stomachs down his food, trying to go to bed as fast as he can. "Goodnight!" he hurries away, ignoring whatever his brothers were saying. He lays in bed, dreaming of his oldest brother having his way with him.

The following days pass by filled with Mephisto's playful glances and winks. They don't act on their desires, at least not that much. While everyone's asleep, they would share brief kisses. It was Mephisto's goal to make Rin needy and it worked.

A bright morning sunlight peeps through Rin's curtains as his alarm goes off. It's Monday morning, a day everyone dreads. He expects Yukio to enter his room and tell him to get ready for school. A few seconds after Rin gathers his thoughts, Yukio opens his door.

"Wake up, Rin," He says, turning on the light.

Rin doesn't want to go. In response, he hisses and pulls his sheets over his head. "I'm sick," he says with a fake cough. The trick wouldn't work, but it's worth a shot.

"Nice try, Rin. I can tell whether you're sick." Yukio replies. When Rin doesn't reply, he sighs in defeat. "Fine. At least come in late. I'll make sure Mephisto drives you." he closes the door.

The mention of his half-brother makes Rin almost crack a smile. They would be alone for quite a while. Amaimon and Yukio go to school, while the old man helps out at his church. Mephisto rarely leaves the house unless he managed to find a job.

Thinking about what they could do together makes the area around his crotch tighten. It's way too early for such thoughts, but Rin can't stop his brain. He begins rubbing his legs together, feeling his cock harden. Outside his room, he can hear his brothers run back and forth while they get ready for school. It doesn't stop him from lowering his sweatpants, his boxers, and whipping his dick out. Under his breath, he whines and cries out Mephisto's name. When he closes his eyes, he can practically see his brother jerk him off. His breathing becomes slow, biting his lip and drooling as his hand moves up and down. After he spills all over his hand, Rin accidentally falls asleep. If anyone walked in, they would see the fun Rin had early in the morning.

It's exactly what Mephisto stumbles upon when he opens Rin's door in the afternoon. "Oh," he chuckles, closing the door. With a sinister grin, he approaches Rin's bed. "Brother, dear? Are you up?" he asks.

"Wha...?" Rin cracks one eye open. When he sees Mephisto, he jumps up. Then he sees himself and the white release all over his lowered pants. "A-Ah! K-Knock next time, asshole!" he hides under the covers out of embarrassment.

"It's twelve in the afternoon, Rin." Mephisto smiles. "You skipped school! Yukio told me to wake you up, but... I see that wasn't on your mind." he cups Rin's cheek when the boy sits up, attempting to pull up his pants. Mephisto stops him and pushes him down on the bed. "What were you thinking about, my naughty brother?"

Rin's heart begins to speed up. This is what he desired. Heat rushes to his face as Mephisto stares him down with a suggestive grin. "N-Nothing," he lies, pulling away from Mephisto.

Mephisto shakes his head in disapproval. He wasn't allowing his brother to lie and play hard to get. "Will this make you remember?" he climbs on the bed, pulling Rin's legs and spreading them apart. Rin gasps when his pants and boxers are taken completely away from him. Mephisto doesn't waste time in grasping Rin's cock, which becomes erect once again. "Tell me, Rin," he starts grazing his thumb on the head of Rin's cock. "How needy are you? To touch yourself without my permission? Who made you like this?"

"Y-You-" Rin replies almost silently, giving breathless gasps as Mephisto jerks him off.

"Hm? I can't hear you." Mephisto pauses, leaning close to his face. Rin is flushed and so adorable. One more cry from him and Mephisto would be seconds away from bending his body in half.

"Please, Mephisto," the younger male whines. He shivers when a pair of lips pressed against his neck, sucking on the skin. His eyes squeeze shut. Why he's so needy and desperate doesn't come across Rin. All he knows is that he wants Mephisto. "It's you," he finally says, allowing a moan to slip out of his lips. His body gets turned sideways, stopping the pleasure momentarily. Rin is confused. He turns his head and spots Mephisto leaving.

Mephisto returns immediately with something in his hands. "Oh, don't give me that look," he notices Rin's confusion. "I don't want to hurt you when I fuck you, dear."

Rin's heart nearly leaps out of his chest. Mephisto kisses his cheek lovingly before turning the boy's stomach. He knows what's coming up next after dreaming about this for so long. His legs get spread so his ass is in full view for Mephisto. The elder brother chuckles as he opens the bottle he has in his hand.

A cold substance coating Rin's ass sends shivers down his spine. He assumed it was some type of lubricant. It made Mephisto's finger fit easily into the younger's tight hole. Rin gasps as the unknown sensation, making his legs tremble. Mephisto preps up so well. Rin grabs onto his pillow and moans as two digits finger him quick.

"Are you going to come at the touch of my fingers, Rin?" Mephisto pauses, his fingers still inside. "I can't let that happen!" Slowly, he pulls out his fingers. He can hear Rin sob. "What a needy brat," Mephisto scolds, undressing. Reaching for the bottle of lube, Mephisto coats his hardened cock.

"Keep going," Rin turns his head. "I'm ready, Mephisto." he's determined to get fucked by his brother. He'll do and say whatever.

"Beg, then." Mephisto grins as he grabs Rin's ass, squeezing it with his hand. He positions his cock right at Rin's hole, just barely teasing the entrance. "Greedy whore."

"Please!" Rin nearly screams. "I can't wait anymore!" he clenches his bedsheets, gasping as Mephisto pushes his cock ever so slowly. "M-Mephisto, please...!"

"So pathetic." Mephisto bites his lip. He decides to stop playing around and thrusts himself fully into Rin, grinding his body. Rin immediately melts, gasping at the sudden pleasure. The only thing one could hear from the room is the sound of slapping skin and Rin's moans. Mephisto indulged in taking his brother's innocence. The boy's body eased and soon got used to the new sensation, begging Mephisto to do more.

Mephisto bit his lip and groaned, imagining Rin's sensual face. It made him pause his movements, remove himself from Rin, and turn the boy around. Rin had tears on his red, wet face, wearing a confused look. Mephisto lifted his legs before going inside him again. With every thrust, Rin gasped, mouth agape. His legs and lips trembled, ready to burst any second. Mephisto leaned down and kissed Rin, silencing their noises for a few seconds.

"Ready to come, dear Rin?" Mephisto cheerfully asked, his movements slowing down. When Rin continuously nodded, he sped up. "Go ahead~" he grinned, licking his lips. Rin gasped, choking on the saliva in his throat. He squeezed his eyes shut and whimpered, his release shooting all over himself. "What a good boy," Mephisto chimed as he kept going. "Don't worry, I'm almost there."

Mephisto paused to release his load inside Rin, gritting his teeth as his body relaxed. Rin gasped, feeling the seed dripping out of his hole. "How cute," Mephisto blushed, kissing Rin. They embraced each other for a while.

Until they heard a car outside. "Oh, fuck," Rin pulled away from Mephisto. "The old man is here! Go!"

"How rude. Kicking me out already?" Mephisto sighed. The car door was shut, loud enough to hear from inside. He rolled his eyes and got up from the bed, grabbing his clothes. Rin glares as he struggles to get together and clean himself. "Don't give me that look." he returns to the bed and pulls Rin for a kiss. "You were a really good boy; you know that? You did so well. I can't wait until we do this again, my dear brother."

The doorknob starts to jiggle. Rin bites his lip and blushes, nodding. "Thank you, Mephisto..." he pulls the blanket, covering his body. "Now go. He's almost here."

"Fine," Mephisto winks, heading to the bathroom for a much-needed shower.

Finally, the front door opens. Shiro's footsteps are heard nearing Rin's door. The old man cracks it open, peeking in. "Huh. Still sleeping?" he sighs. "Lazy child." the door closes for good. Rin releases the breath he was holding in.

Later in the day, everyone has gathered around for dinner. For once, there's no fighting going around. Rin is too tired and sore to argue with Amaimon. Yukio isn't yelling at Amaimon for having horrible table manners. Mephisto is himself as always, unbothered and cheerful.

"I'm glad you guys are getting along," Shiro chimes in, breaking the silence. "It makes me feel like a proud father." he wipes an invisible tear. Mephisto smiles at Rin, who hides his blush by drinking his beverage.

Amaimon pokes his food with his fork, grinning. "We all have different methods of getting along."

Rin nearly chokes. He eyes Amaimon. _You didn't?_ He inaudibly mouths, then looks at Yukio.

Yukio excuses himself from dinner.

"We're all loving brothers," Mephisto adds on with a grin.

Rin feels like dying right on the spot. _What is up with this family?!_

**Author's Note:**

> I might make a second chapter with Yukio and Amaimon if this does well??


End file.
